sadly.. there's not much user using skype VC.
I'ved try to use it couple month.. but not many friend use it.
Another thing is.. not practical during working time. (you can't use headphone + mic), your boss will say "You're fired!"..
But chat message always can. (of course some office admin blocked it)
I do chat during working time, after finishing my task or asking related people regarding works ie : coding, solving problem etc.
So.. YM still the best for me.. (and you can use it to chat with somebody with MSN id too).
Friendster and myspace, it both sux, unless you're social type of people.
And a bit childish look for me. (most of them teenagers, early teenager = under age one
) And myspace will slow down you connection ie: 1 profile view = 10 video X 1mb = 10mb hahaha.. and the sounds also anonying ..